Continuous flow centrifuge rotor and liner element



Sept. 17, 1963 c.D1 BENEDETTO 3,104,225

CONTINUOUS FLOW CENTRIFUGE ROTOR AND LINER ELEMENT Filed Jan. 29, 1960 I N V EN TOR. E v5/ARL. E5 D/ EEA/505770 AEEWT United States Patent 3,104,225 CNHNUOUS FLGW CENTRIFUGE ROTOR AND LINER ELEMENT Charles Di Benedetto, Brooklyn, NSY., assigner to Lourdes instrument Corporation, Brooklyn, NY. Filed lan. 29, 1950, Ser. No. 5,533 7 Claims. (er. 233-28) This is a continuation in part of the abandoned application, Serial No. 718,893, tiled March 3, 1958.

'This invention relates -to a continuous flow centrifuge and more particularly to the rotor and l-iner element.

The Word centrifuge as used throughout this specification is to be understood as primarily a laboratory instrument wherein a rotor or central bowl is rotated at extremely high r.p.m. (2,0'G0-20,0O10). With this high r.p.n1. there is an enormous centrifugal force developed. This centrifugal force is utilized for the separation of mixtures.

A high speed continuous flow centrifuge is not entirely new in the art. However, the attempts to devise such a device have been poorly designed and lacking in foresight. For example, if the rotor bowl yor mixture container is not lined or protected there is a delay in cleaning the rotor bowl after each operation.

The prior art for one type shows that .the rotor must be stopped and the rotor must be taken `from centrifuge and the materials removed from rotor, then rotor must be cleaned to be reassembled for next run. lf refrigeration is required, then rotor must be first chilled before it is ready for the next run. All of this provides a considerable delay, this delay may also be harmful to the mixture being separated.

In another type used in the prior art in which test tubes are used for collection, these require more time for disassembly, cleaning and reassembly and the capacity is considerably less.

With continuous flow of the mixture to be separated in this invention, there is `a definite relationship between the inlet and outlet. The inlet must be centrally positioned and should be inserted suiciently within the central aperture to permit feeding the charge to the rotor to provide the best circulation from inlet to outlet to permit centrifugal force to act upon the density of the mediums in the mixture, the denser mixture being thrown outward while the lighter medium circulates from the inlet to the outlet, yor the denser particles will be thrown outward and downward while the remaining Huid or medium ows according to the induced circulation. This circulation must also be carefully controlled, that is, the feed must be slow where mediums have similar density and feed m-ay be increased where there is a greater difference in density.

It is an object of this invention to provide a continuous flow centrifuge in which the high speed rotor is formed generally in fthe shape of a circular bowl to receive a continuous flow of a mixture from a central inlet port and in which the rotor receiving this flow is in turn connected to an outlet port.

It is a further object of this invention to provide a continuous flow centrifuge in which the high speed rotor is formed generally in the shape of a circular bowl and is provided with a plastic removable liner that will abut with the entire internal surface of the bowl shaped element to receive a continuous flow of mixture from a central inlet port and in which the rotor receiving this flow is in turn connected to an outlet port.

It is a further object of this invention to provide a continuous flow centrifuge in which the high speed rotor is formed generally in the shape of a circular bowl and is provided with a plastic removable liner such as polyeth- 3,104,225 Patented Sept. 17, 1963 ice 2 ylene that will abut with the entire internal surface of the bowl shaped element and in which the liner is provided with an enlarged lip around` the mouth of said liner to assist in sealing said baglike liner wtihin the rotor, to receive a continuous flow of a mixture from a y central inlet port and in which the rotor receiving this flow is in turn connected to an outlet port.

It is a further object of this invention to provide a continuous flow centrifuge in which the high speed rotor is formed generally in t-he shape of a circular bowl and is provided with ancoating of plastic covering the entire internal surface of the bowl shaped element to receive a continuous flow of a mixture from a central inlet pont.

and in which the rotor receiving this flow is in turn connected to an outlet port.

It is a further object of this invention to provide a stationary inlet tube and in which a discharge cap mounted concentrically about said stationary inlet and in which the discharge cap is formed with an enlarged enclosure about the periphery of the outlet portion toy insure a predetermined pattern of circulation.

It is a further object .of this invention to provide a continuous flow centrifuge in which the high speed rotor is formed generally in the shape of a circular bowl and is provided with a removable flexible container that is concentric in form that willr fit within Ithe entire internal 'is formed generallytinrthe shape of a circular bowl, the

circular bowl is provided with an angular shaped wall,` and is providedtwith a plastic removable liner such as polyethylene that will abut with the entire internal surface of the bowl shaped element and in which the liner is provided with an enlarged lip around `the mouth of said liner .to assist in sealing said liner within the rotor, to

receive a continuous flow of a mixture from a .central Y inlet port, and in which the denser mixture or will irnpinge on the wall and flow down-ward.

Further objects of this invention shall be apparent by reference to the accompanying Idetailed description and the drawings in which:

L FIGURE 1 is a cross sectional rotor, and

View of the centrifuge FIGURE?. is a further embodiment of this invention. i Referring to the drawings, and particularly FIGURE 1,

there is illustrated a rotor 1|)` that is designed to be inserted on a central shaft 11 of a centrifuge. provided with a circular` bowl-shaped interior 12 and in cross section the interior of the bowl assumes the outline of a pair of pockets but actually the pockets are joined into a single concentric configuration as shown in the drawing. The wall 14 is angularly disposed, so that the bottomor floor 15 of the bowl is further from the central axis than the upper inlet portion of the bowl. The reason for this formation is that when the rotor 10 is rotated at high speed the mixture being fed into this bowl will be` thrown outward by centrifugal force and the heavier par- ,1

particles The rotor 10 isticles or denser medium will imping with the angular internal wall and thus ow downward towards the floor or bottom of the bowl. The rotor 10 is provided with a sealing cover 16 toclose the bowl area. Cover 16 is in turn provided with a central threaded aperture 17. A discharge cap 18 is provided and is formed with thread 19. This thread 19 is of a diameter and thread to lit the threaded aperture 17 of element 16. The discharge cap 18 has an internal bore 20. The mouth of bore 20 is of a diameter to fit loosely about the periphery of a stationary inlet tube 22. Inlet tube 22 may be supported by means not shown. The opposite end of bore 20 is connected with smaller diameter apertures 23, which extend radially from bore 20 and the lower end of bore 20 is closed or sealed. Element 18 in cross section is formed generally in the form of an inverted T. The lower enlarged end 24 is provided with the plurality of bores 23` which extend from the periphery of the bore 2t) to a point within the rotor bowl. Element 18 is also provided with a cone shaped extension 26, extending from the lower surface of the inverted T-shaped element 18 to a point below and in close proximity to the raised central portion of the rotor. The stationary tube 22 passing through the discharge cap 18 extends down into the internal bore 20. While the bores 23 lead from bore 20 comprising the outlet, at the upper end of element 18 there are provided a plurality of ports which are connected by tubular elements 31 to the area within the cone shaped element 26 above the center of the rotor 10, thus providing the outlet ports for the fluid or mixture leaving the rotor. The collector to enclose these ports to accumulate the outlet mixture is not shown and is not part of this invention.

With a structure such as that described and illustrated in FIGURE 1, a centrifuge operation is possible, that is, if a mixture to be separated is fed through tube 22 and the rotor 10 is rotated at the desired r.p.m. The mixture entering through inlet port or bore 2()y will feed downward to the bottom of bore 20, where it will be thrown outward by centrifugal force through the plurality of bores 23 to irnpinge on the angular walls 14 of the rotor 10. However, the particles being thrown outward will actually impinge against the internal surface of an inserted liner 32. The heavier particles or denser fluids will move downward as indicated lby arrows and as the bowl becomes filled with the mixture the lighter particles or medium of lesser density will be displaced by the heavier particles or medium, forcing the lighter medium through the outlet area between the rotor center and the covering cone shaped element 26, this rotating medium of lesser density will be forced upward through this area and into the connecting tubular elements 31 and on upward until the medium reaches the outlet ports 30, where the medium of lesser density will be thrown outward by centrifugal force into the collector (not shown). As more of the mixture is introduced through port 22, it will build up a circulation from port 22 indicating a ow of heavier particles towards the internal surface of bag 32 and a flow of lighter medium toward ports 30. Thus the separation will take place immediately under centrifugal force and as the head or rise due to the feed of additional mixture forces the lighter medium through tubes 3'1, the mixture will build up until it reaches the outlet port Sil. Thus, as the mixture is fed in through tube 22 it will be separated and will continue to expel the lighter medium or particles along the circulation path described until there is a build-up of the heavier particles or medium in the bowl. 'I'he rotor must be stopped when the heavier particles show at the discharge.

This invention includes the use of a plastic liner 32. The liner is preferably of an exact size but may be either flexible or stretchable to permit the bag shaped liner under centrifugal force to conform with the entire internal surface of the rotor. The liner 32 is also provided with an enlarged lip 33 and the under surface of the cover 16 is provided with two O ring seals, 34 and 35. The circular seals press on the lip of the baglike liner that rests on the upper surface of the rotor, thus the sealing cap 16 may be threadably secured to the rotor 14 and will impress sufficient force on the lip 33 to provide a perfect seal. The liner 32 may be formed of polyethylene and will thus be capable of being sterilized with gas before each operation rather than having to sterilize the internal surface of the bowl. Likewise, the liner 32 maybe quickly removed from the rotor after one operation, and a second liner may be quickly inserted and a second operation may be started without delay.

It is apparent that various materials may be handled by this centrifuge with a bag liner that could not normally be handled because of the effect of their contact with the metal of the rotor.

A further embodiment of this invention would be to provide a container with a certain degree of flexibility but preformed to tit the internal bowl of the rotor and a still further embodiment of this invention would be to coat the entire internal surface of the rotor bowl with a plastic protective coating, such as Teon (polytetratluoro ethylene).

A'still further embodiment of this invention is illustrated in FIGURE 2 in which the rotor 10A is formed with a different shaped interior bowl 12A. Thus, the liner 32A may be a flexible plastic liner as in the prior embodiment or it may be a semi-rigid preformed container of concentric `form that is easily bent or distorted to snap into and to t the internal bowl 12A. However, in this embodiment, the rotor is not provided with a raised central portion and the base of the T-shaped element 18 is provided with a concentrically formed tubular extension 26A, which extends to a position in close proximity to the bottom 15 of the bowl shaped area. Otherwise, this embodiment is similar in every other aspect to the prior embodiment. This particular embodiment provides a rotor for small volume sediment collection.

It is to be noted in both the embodiments described that the fluid mixture to be separated actually starts its separation the instant it is introduced into the rotor and impinges with the bottom surface of the rotating bore 20. The enormous centrifugal force developed by the rotor spins the impinging mixture and throws it radially outw-ard to again impinge against the angularly formed internal wall of the rotor. As already described, the greater force induced into the heavier particles will cause them to cling to and slide down the angularly formed wall of the rotor to gather in Ithe base of the bowl as shown in the drawings. The lighter particles or fluid will of course rst tend to till the bowl of the rotor, but `as the charge of material continues, the lighter portion of the mixture will be forced toward any outlet in the bowl. Since tubes 31 are the only outlets on Awhich the centrifugal `force is not acting, then the lighter uid will be forced up through these tubes to be expelled from the rotor. Actually the iluid rising from the tubes 31 will again be effected by the centrifugal force to be thrown otf in a radial pattern into a collector (not shown). The pattern of circulation developed permits a continuous feed of uid mixture and a continuous expulsion of the lighter medium until the bowl of the rotor becomes loaded with the heavier particles. When the bowl is iilled with the heavier particles the `rotor is stopped, the liner is easily removed and a new liner inserted, and the operation is then continued without the usual delays found with all other rotors.

Various changes may be made to this invention, such as the size or shape of the bowl of the rotor, without departing from the spirit of this invention, and various liner materials may be utilized without departing from the spirit of this invention, and this invention shall be limited only by the appended claims.

What is claimed is:

l. A rotor that is charged to provide continuous flow centrifugation and which includes a hollow rotor, a cover and a `discharge cap, said rotor formed as a circular bowl with an open top and circular walls and the internal surface of said walls slanted in :an angular formation with the top of a smaller diameter than the base of said rotor, said rotor ion its under side formed with a mounting land driving socket for the insertion of a drive shaft, said rotor also provided -with la raised central portion within said bowl shaped area, said cover threadably secured to the open top of .said rotor and provided with a central aperture, said discharge cap threadably secured in said central aperture on the under side of said cover to extend into said rotor, said discharge cap provided with a central aperture through which a stationary inlet tube may be mounted to convey material into the rotor, said central aperture of said discharge cap extending into said cap to a point below said cover and a plurality of bores extending radially from said central aperture at this point, said radial bores extending into the interior of the rotor bowl toward the upper portion of the internal surface of the ywalls of said rotor, said discharge cap formed at its lowest penetration into said rotor bowl with a cone shaped extension that surrounds and is in close proximity to the raised central portion of said rotor bowl, said discharge cap provided with laterally spaced discharge tubes that extend from Within the cone shaped extension at the bottom surface of the cap to the top surface.

2. vIn -a device according to claim 1, in which the internal surface of said walls of said rotor is provided With an easily removable, stretchable, liexible liner, formed generally bag shaped, to adjust its shape under centrifugal force to the internal contours of said rotor.

3. In a device according to claim 1 in which the i11- ternal surface of said Walls of said rotor is provided with a liner of polyethylene ,to protect said rotor internal bowl from the harmful effect-s of any fluid mixture.

4. In a device according to claim l in which the vdischarge cap is provided with a dat top surface, the said laterally spaced discharge tubes carrying the separated uid rising therein to said iiat top surface to be thrown olf Iradially from said surf-ace by centrifugal force.

5. A rotor that is charged to provide continuous ow centrifugation and which includes a hollow rotor, a cover and a discharge cap, said rotor formed as a circular bowl with an open top and circular walls and the internal surface of said wall slanted in lan angular lformation with the top of a smaller diameter than the base of said rotor, 45

said rotor on its under side formed with a mounting and driving socket for the insertion of a drive shaft, said cover threadably secured to the open top of said rotor and provided with a central aperture, said discharge cap threadably secure-d in said central aperture on the under side of said cover to extend into said rotor, said discharge cap provided with a central aperture through which a stationary inlet tube may be mounted to convey material into the rotor, said central aperture of said discharge cap extending into said cap to `a point below said cover and a plurality of bores extending radially from said central aperture at this point, said radial bores extending into the interior of the rotor Abowl toward-the upper portion of the slanted internal surface of the walls of said rotor, said discharge cap formed at its lowest penetration into said rotor bowl with la cylindrical extension that surrounds and is in close proximity to the central portion of said roto-r bowl, said discharge cap provided with laterally spaced discharge tubes that exten-d from within the cylindrical extension at the bottom surface of the cap to the top surface.

6. In a device according to claim 5 in which the internal surface of said Walls of said rotor is provided with a semi-rigid preformed container of concentric form that is easily distorted to snap into and iit the internal bow-l of said rotor.

7. In a device according to claim 5 in which the bottorn surface of the central aperture forms a spinning disc for the separation of a uid mixture as it impinges thereon.

References Cited in the file of this patent UNITED STATES PATENTS 447,530 Wahlin Mar. 3, i1891 596,508 Hohnsbehn Jan. 4, 1898 `631,68() Svtaahlgren Aug. 22, 1899 636,780 Evans et al. Nov. '14, 1899 732,886 Odell et al. July 7, 1903 2,084,4871l H-aralldson June 22, 1937 2,186,836 McGlau-ghlin Jan. 9, 1940 y2,321,144 Jones June 8, 1943 2,822,126 Cohn Feb. 4, 1958 2,883,103 Whitehead et al. Apr. 2-1, 1959 FOREIGN PATENTS 971,978 France Aug. 23, 1950 

1. A ROTOR THAT IS CHARGED TO PROVIDE CONTINUOUS FLOW CENTRIFUGATION AND WHICH INCLUDES A HOLLOW ROTOR, A COVER AND A DISCARGE CAP, SAID ROTOR FORMED AS A CURCULAR BOWL WITH AN OPEN TOP AND CIRCULAR WALLS AND THE INTERNAL SURFACE OF SAID WALLS SLANTED IN AN ANGULAR FORMATION WITH THE TOP OF A SOALLER DIAMETER THAN THE BASE OF SAID ROTOR, SAID ROTOR ON ITS UNDER SIDE FORMED WITH A MOUNTING AND DRIVING SOCKET FOR THE INSERTING OF A DRIVE SHAFT, SAID ROTAR ALSO PROVIDED WITH A RAISED CENTRAL PORTION WITHIN SAID BOWL SHAPED AREA, SAID COVER THREADABLY SECURED TO THE OPEN TOP OF SAID ROTAR AND PROVIDED WITH A CENTRAL APERTURE, SAID DISCHARGE CAP THREASABLY SECURED IN SAID CENTRAL APERATURE ON THE UNDER SIDE OF SAID COVER TO EXTEND INTO SAID ROTOR, SAID DISCHARGE CAP PROVIDED WITHA A CENTRAL APERATURE THROUGH WHICH A STATIONARY INLET TUBE MAY BE MOUNTED TO CONVEY MATERIAL INTO THE ROTOR, SAID CENTRAL APERATURE OF SAID DISCHARGE CAP EXTENDING INTO SAID CAP TO A POINT BELOW SAID COVER AND A PLURALITY OF BORES EXTENDING RADIALLY FROM SAID CENTRAL APERATURE AT THIS POINT, SAID RADIAL BORES EXTENDING INTO THE INTERIOR OF THE ROTOR BOWL TOWARD THE UPPER PORTION OF THE INTERNAL SURFACE OF THE WALLS OF SAID ROTOR, SAID DISCARGE CAP FORMED AT ITS LOWEST PENERTRATION INTO SAID ROTOR BOWL, WITH A CONE SHAPED EXTENSION THAT SURROUNDS AND IS IN CLOSE PROXIMITY TO THE RAISED CENTRAL PORTION OF SAID ROTOR BOWL, SAID DISCHARGE CAP PROVIDED WITH LATERALLY SPACED DISCARGE TUBES THAT EXTEND FROM WITHIN THE CONE SHAPED EXTENSION AT THE BOTTOM SURFACE OF THE CAP TO THE TOP SURFACE. 